how long has your tank been set up, because if you have the 2 damsels for cycleing then i think its okay to keep them, but after the cycle is over belive me you WILL want them outa there,personally i like the way they look, but if they wasent such a pain in the butt with being REALLY aggressive then i would, but due to there aggressiveness there is a posiblty that they can and maybe will chase(and or kill) other fish, and if there not showing signs of being aggressive now , give it time, i havent expericaned this but i have heard that they dont start off too bad, but they get very aggressive towards newcomers , if u wanna try ur luck, i can wish u the best of luck(your gonna need it)